Underreamer



April 51927.

fr y 23 57 24 g., e.; Y j@ a6 16 i? n 0 28 47 .71

w. R. WILBER UNDEBREAMER Filed Nov. 13, 1925 2 sheetsshe.e+v 1 5&7@ 1'had literary v Patented pr. 5, 1927.

, vUNITED ls'lxal'rl-:s

WILLIAZ-M E. WILBER, 0F LOS ANGELES, CALIFO'RNIA` UNDERREAMER.

i Application led November 13, 1925. Serial No. 68,810.

This invention relates to under-reamers of ythe type employed in welldrilling operations for enlarging the well. bore below the lower end ofa well casing, so that the latter may be readily lowered into the well,and particularly pertains to improvements in underreamers of thecharacter set forth in United States Letters Patent No. 1,511,385,issued to me October 14, 1924.

Under-reamers of this type include in their ensemble a shank adapted tobe lowered through a well vcasing on which shank is carried a pluralityofl cutters adapted "to be advanced and retracted laterally and includea mechanism whereby the cutters are automatic'allyexpandedl afterpassing through a well casing andprojected into the well bore apredetermined distance below the lower end o`f-the well casing, andembody means for locking the blades in their expanded position operableon withdrawing the shank through the well casing to release the cuttersand permit them to move to their retracted position and allow the toolto be drawn through the well casing. The cutter actuating mechanismembodies a spring-pressed slide bar adapted to effect a wedge action onthe cutters in accomplishing expansion thereof andv includes slideblocks guided on the shank adapted to be engaged by the well casing andoperable in such manner as to shiftthe spring-pressed slide bar inopposition to the spring-pressure thereon in effecting freeing of thecutters, and which. slideblo'cks and spring-pressed slide barl are socooperatively arrangedthat when the springpressed slide-bar is retractedto effect spread or expansion of the cutters, the slide-block will bepositioned to project beyond the general outer periphery of theunder-reamer sh'ank.

' The present invention pertains to, and has as one of'its objectsthe`provision of, improvements in the construction and mounting` of thecutters whereby the latter will be securely supported bythe body orshank of the reamer so as to withstand the strains imposed thereon ywhenin their expanded and operative position.

The invention further pertains to the constructionfandmounting of theslide block with the view of simplifying the construction and insuringproper functioning thereof in eifecting actuation .of the cutterexpanding and retracting means.

y.Another object is to provide anu-nderreamer of the above character inwhich the parts may be readily assembled, which is not liable' to getout of order and is adapted to endure hard service. v

With theforegoing objects in view, together with s uch otherobjects andadvantages as may subsequently appear, the invention further-'resides inthe parts, and inthe combination, construction and arrangement of parts'hereinafter' described and claimed and 'illustrated by way of examplein the accompanying drawin s, in which Fig. 1 is a View o theunder-reamer as seen in vertical section and showing it as applied withthe cutters disposed in their expanded under-reaming position.; f

2 is a detail in vertical section showing t e cutters as disposed intheir retracted osition as when being lowered or withrawn through a wellcasing;

Fig. 3 is a perspective view of one of the slide blocks;

Figs. 4 and 5 are fragmentary views in vertical section showing one othe slide blocks in its up ermost and lowermost posi-` tions respectivey Fig. 6 is a detail in horizontalsection as seen on the line'6'-6 ofFig. 1;

Fig. 7 is a' view in horizontal sectionA as seen on the line 7--7 ofFig. 1;

Fig. 8 is .an enlarged horizontal section as seen on the line 8-8 ofFig. 1;

Fig. 9 is an end view of the under-reamer` with the cutters advanced asshown v in Fig. 1;

- Fig. 10 reamer;

u Fig. 11 is a mounting thecutters, and showing the parts as positionedto dispose 'the cutters in their advanced position; the view showingoneof the cutters removed;

\ Fig. y12 is a view in section and elevation detail in section andelevation illustrating the manner of forming andis a perspective view.of the under- -illustrating a cutter as disposed in its retractedposition;

Fig. 13 is' a view' inside elevation, partly in vertical section, of thelower end portionof the under-reamer as viewed looking toward thecutter;

Fig. 14 is a perspective view-'of one of the cutters as seen -from therear side thereof; and f Fig..15l is a perspective view of the lower 'nof through the recesses 18 and -brought into' cifically, 16 representsthe shank or body member of the reamer which is o f tubular cylindricalform and is of such diameter thatv when inserted in' a well casing,indicated at 17, the outer periphery of the shank will he spacedslightly from the inner surface .of the well casing to afford aclearance. The lower end of the shank 16 is formed with a transverseslot opening to` the lower end of the shank, the side walls of whichslot are formed with opposed vertically extending recesses 18, as shownin Figs. 8, and 11, and are also formed with depressions 19 and 20having outer marginal walls 21 which in cline outwardly and downwardlyand constitute shoulders that serve as abutlnents for limiting outwardmovement of cutters A and B; the lower margins of the recesses 21 beingarcuate and serving as ledges on which the `cutters A and B aresupported through the medium vof laterally projecting side flanges C andD formed on the cutters: the 'lower ends of the flanges normally seatingon the end walls 22 and beingrv adapted to abut against the inclinedwalls 21 to limit outward movement of the cutters. The upper ends of thecutters Aand B are designed to seaton the upper end of the slot in theshank so as to abut upwardly aga-inst the shank when the cutters are intheir outermost or expanded positions, as shown in Fig. 11.

In order that the cutters Amay be positioned in the slot withjhe flangesC and D thereon extending. into the recesses 19 and 20, the recesses 18open to the lower end of the shank between the ledges, 22, as shown in11, so that the flanges (lv and D may be 'passed position in therecesses 19 and 20, as in assem'bhng the cutters, and also to permitremoval of the cutters. The lower ends of thev cutters are provided withcutting heads E, the outer faces of which are curved on the arc of acircle whose diameter is equal to the diameter of the hole to -bereamed. The

lower faces F of the cutters are flat and ineline upwardly andinwardlj,4 from the outer ably conform to the side walls of the end.lslot in the shank and are of lateral breadth that when the cutters aredisposed 1n thelr'retracted positions, as shown in Fig.

.2, their outer faces will lie substantially within the boundary of acircle whose ldiameter' is less than the internal 'diameter of the wellcasing. Y

Arranged in the tubularbore 23 of the shank 16 is a slide-bar 24 whichis formed with a reduced upper end portion, as indicated at 25, aroundwhichis wound a coil spring 26, the upper end of which spring bearsagainst av collar 27 formed on the slidebar and the lower end of whichbears on a key 28 extending through a slot 29 formed in the slide-bar;the key 28 having its end portions projecting into opposed slots 30formed in the .shank 16 and through which slots the key may be readilyremoved and replaced. The key 28'is normally held in a seated positionagainst the bottoni walls of the slots 30 under the 'action of thespring26 and is held against longitudinal ldisplacevment by meansof a lug 31on the key projeeting` 'downwardly into the bore23. The

slots 30 are of such vertical width as to permit the key l28 with itslug 31 'being passed therethrough either in putting the key in place orremoving it. Spaced downwardly from the key 28 is a second key 32 whichpasses through a transverse slot 33, formed in the slide har and alsoextends into opposed slots 34 in the shank 16 through which the key 32may be readily removed and replaced.A

An upwardly extending lug 35 on the key 32 projects into the bore 23 toengage' the walls of the latter whereby the key -32 is normally heldagainst longitudinal displacement. The outer end portions of the key 32project into the field of siderecesses 37-on the shank. the side wallsof which recesses are formed with inturned flanges 38 on their oppositeouter marginal edges forming guidewa-ys. Slide blocks G are mounted inthese guidewajas., the formation of which slide blocks is particularlyshown in Fig. 3; the slide blocks including oppositely extending sideflanges H and Iwhich project into the guide-l .ways and underlie theflanges 38 whereby the slide blocks are held in placepwithin the.guideways The. slide blocks `are each formed with inturned endvportions'J and K and are beveled at the intersection of their upper andlower end faces with their outer faces, as 1ndieated at L and M. Theupper faces of the' projections J and K are also beveled, as indicatedat N and O. j y

The slide blocks normally gravitate to ,a position with their lower endsseating on the outwardly projecting end portions of the key 32 and areadapted to move vertically in their guideways to effect downward nieve-'ment of the slide-bar or under the influence 'of'upward movement of theslide-bar, as oecasion may be, and as will be later described.

When the slide bar is disposed in its lowermost position` as shown inFig. 2. the slide blocks (lr seating on the key 32 will he disposed inan` innermost position with the i'nturned end portions .T and K thereonprojecting into transverse slots P; andv Q. formed in theshank, as shownin Fig. 5. The upper walls of the slots P 'and Q are inclined out--wardly and upwardly, as indicated at R and 1S, respectively, and theupper faces of the projections J andv K on the .slide-block are likewiseinclined so that upward pressure imparted `to the slide-'blocks when intheir lowermost position, as shown inl Fig. 5, will cause these blocksto ride out of thel slots P and 'Q so thatthe slide blocks may movevertically with the slide-bar into the position shown in Fig. 4, withthe projections 'J and Kon the slide-block Seatingv on the shank andwith their outer Vportions prioljecting beyond the 'boundariesof acircle having a ianieter corresponding to the internal dlamete-r of thewell casing whereby after passing the tool shank through the well casinga sutlicent distance to dispose the slide-blocks beneath the lower endof the casing with the slide-'blocks disposed in their outermostpositions, the latter will be engaged by the lower'end ofy the casing onthef'lifting of the-tool shank so as to cause the slide-blocks to movedownwardly in i their guideways vand .thereby cause them to act throughthe key 32 to advance' the slidebar 24 downwardly in opposition to theAsa means vfor facilitating mounting and demounting ofthe slide blocksthe 'recesses .130.,

38such'distance as to permit the slide blocks beingi disposed in' therecesses and then 37 are continued above the inturned flangesLegliwardly therein to bring the side `-the slide blocks beneath theinfanges fb turned flangesySS. After thus p sitioningthe slide' blocksin the guidewa s the extended portions of the recesses are filled byremovable plates 40 secured in place by' screws 41, vthe lower ends ofwhich plates extend adjacent to the guideways and lserve- -tol` limitupward movement of` the slide blocks.

-1 lbetweenthe cutters A and B and terminates imac-@head 41 whichprojects beneath the Vcutters so that it may enter the bore in ad-lAVance of the cutters and ser-ve to assist in I guiding and centeringthe cutters as the tool advances; the -head 41"-'being 'preferablyformedvwith its lower end AI )'irtions substantially wedge-shaped asshown in Fig. 15.

The -head 41 is enlarged with relation to i the slide-bar on which it iscarried. and is vformed with transversely extending shoulders. 42projecting from opposite sides .of lthe slide bar, which shoulders areadapted to abut against the lower end of the shank 16 when the slide-baris disposed in its uppermost-position, as particularly shown in Figs. 1and 11, and projectingupwardly froml the shoulders 42 are dove-tailedextensions 43 which slide-bly engage channels 44 formed in the, shank16, which extensions serve to .hold the flower end portion of thes1idebar aga-inst lateral. displacement.

Formed'at thet'intersection of the he-ad41 with the slide-bar 24 are,inclined ledges 45 leading downwardly from opposite sides of.

Formed on opposite sides of the"slide-b'ar,

la short distance above the inclined ledges 45 are oppositely extending-inclined protub erances-46 which, when the slide-bar is in ltslowermost posltion, proliect into recesses 47 formed -on the inner facesofthe cut-ters,A

and which protuberancesoperate toy spread the upper end portions ofthecutters when the slide-bar is inv its uppermostv position,r

thus co aeting with lthe inclined ledge345 in shifting the cuttersoutwardly in relatlon to each other to their Iexpanded positions-at boththeir upper 'and lower ends; `the protubera'nces 46 and the inclinedledges' 45- being so proportioned in relation to the transverse widthsof the recesses 19. and 20 on the shank and the shoulders C and D on thecutters that-when the slidefbar is in its uppermost position the cutterswill be -moved outwardly to a position "with the iangesC and D abuttingagainst the shoul-.

ders 21 with the upper inner end portions of the cutters abuttinglagainst the p'rotu-4 berances 46 land with the lower end portions of thecutters seating on the beveled -faces 45'y at thev sides ofI the head 41as 'particu-I A lar'ly shown in Figs. 1 andll` thus securely holding thecutters against Ainward movevment when' in their expanded and cuttingposition.

Formed on opposite sides of the cutters are shoulders 48v which 'projectbeneath the lower endl of the shank- 'and4 serve in cooperation with theabutmentlof the upper ends of the cutters against the shank 4intransmittingend thrusts on the `cutters directly to the shank.

In assembling the under-reamer, the eutters A and B are first put inplace as before. described, and the slide-bar 24 with the spring 26thereon is inserted in the bore 23 ofthe lshank 16 from the lower endofthe latter and advanced to nearly its uppermost position relative', tothe shank, whereupon the key-32 is put in place through the slots 34 inthe shame-and' key 28 is thenput in position through the slots 30; thespring` 26 being engaged by a suitable tool and held in retractedposition during placement ot the key 28 On release of the spring thelatter les will bear on the key 28 and will thenact to maintain theslide-bar in its uppermost position. The slide blocks -are then disposedin their guideways as before descrilbed, thus completing assemblage ofthe too i In the application and operation of the invention. the reameris atlixedto the usual drill stem in -an ordinary manner and preparatoryto its being passed through the well 'casing 17, the slide bar is drawnforward under opposition of the spring 26 so that the cutters A and Bmay be disposed in theinretracted positions. as shown in Fig. 2.whereupon the slide blocks are positioned so thatI their lower-ends willabut 0n the key 3Q with theirI inturned end portions extending into theslots P and Q 't'ormed in the shank. The reamer may now be inserted inthe well" casing and vpassed therethrough: the slide blocks being heldin place in the slots P and Q b v the well casing until the reamer islowered to a position below the lower end of the casing, whereupon onthe slide-blocks being relieved by the casing the spring Q6 will urgethev sl1de-bar24 upwardly thereby causing vthe slide blocks to ride outof the slots P and Q, into the position shown in Fig. Al: the slide-barin moving upwardly under the Aurge of thespringl also acting to eii'ectexpansion of the cutters through the medium of the inclined ledges 45and the protuberances 46 whereby the cutters are disposed in'` theirouterlnost under-reaming position. as before described.

It isto be noted that when the cutters are in their expanded positionstheir upper ends will seat directly on the shank and the shoulders onthe cutter heads will bear on the lower end of the shank'to oppose eu'dthrust of the cutters, and their upper inner portions will bear directlyon the slide-bar, while the lower ends of the cutters will seat on thesides of the head 4l thus opposing any inward movement ofthe cutters bythrust imposed thereon during their underrea.1ning opera tions.

It will be seen that. the upper portions of the cutters in bearingdirectly on the slide-bar from oppositesides thereof will oppose'eachother. so that a. thrust imposed on the blades directed toward thecenter of the shank will be transmitted-to the opposite cutter andthence to the shank through.v

the flanges C and D: outward movement 'of the cutters being` limited byreason of the` abutment of the flanges C and D against the shoulders 21on the shank. When the parts 1 are thus positioned the cut-tins.Yedges'of the under-reamer cutter willvbe'disposed so as to reamthe wellbore of a. diameter to ac'- commodate the well casing.

Vhen it is desired to remove the reamer it is drawn upwardly into thecasing, which upward movement causes the slide blocks to be engaged bythelower end oit' the c asing and to be momentarily held duringcontinued upward lmovement of the reamer shank relative' thereto, untilthe slots P and Q, in the shank are brought opposite the inturn-ed endsof the slide block, whereupon the latter moves inwardly so as to passinto thecasing. This relative movement of the slide blocks and shanketl'ects a relative downward movement of the slide-bar so as to disposethe head fil and the protuberances 46 out ot their spreading engagementwith the cutters so that as' the -reamer is drawn upwardly into thecasing, the latter will engage the outer face ot' the cutters and act toshove the latter inwardly into their retracted positions.

lVhile I have shown and described a specitic embodiment ot' myinvention, I do not limit myseltI vto the exact details of constructionand the arrangement shown, but may employ such changes and modificationsas their upper and lower ends, and means for i .limiting outwardmovement of the cutters.

2. In an under-reameiga shank formed with a central bore, a slide-barextending through said bore and projecting through the lower end of saidshank, a head on said slide-bar adapted to abut against lthe lower endof the shank when said slide-bar is in its uppermost position, a pair ofdove-tailed extensions on saidhead slidably engaging the side channelson said shank, opposltely inclinedledges at the intersection of` thehead and shank, a pair of 'cutters slidably supported by saidshank'adapted to be positioned with their lower-ends seating on saidledges, and means on said slide-bar cooperating with said ledges toeffect expansion of said cut-ters. y

3. In an underrean'1 er,=a shank formed with a central bore and having atransverse slot opening at its sides and lower end, the.

side walls of which slot are formed' with recesses having arcuateshoulders forming ,i their lower margins, a pair-of cutters ar-`rangedin said slot, flanges on said cutters extending into'saidyrecesses and seating onv sald shoulders, a slide-.bar arranged 1n thebore in said'shank having oppositely inclined ledges arranged to engagethe lower ends ot'v said cutters and operable to effect spreading of thelower end portions of the .cutters on upward movement .of the slidefbar, protuberances on said slide-bar operable to 4effect, spreadingofthe-up er end portions of said cutters on upwar movementof saidslide-bar, and shoulders on said shank cooperating with said flanges tolimit outwardvmovement of said cutters.

4. In an under-reamer, a shank formed with a central bore and having atransverse slot at its lower end, a pair of cutters slid# ably supportedin said slot, a slide-bar reciprocably mounted in the" shank bore,spring means for advancing said slide-bar in an upward direction, meansoperable on upward movement of said slide-bar for ef- 20 fleetingexpansion' of said cutters, a transverse'key carried by said slide-barprojectpair of slide blocks carried on the'sides of said' shank,guideway's onv the shank in which said blocks are slidablelongitudinally of the shank, spaced inturned projections on said slideblocks adapted to seat -on the 'bottom' of their guiding channelswhereby the outer portions of said slide blocks protrude beyond theperipheral face .of the shank, said slide-blocks being adapted wiLLIAMR. WILBER.. y

'ing through side -openings in saidfshank, a

soA

